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Related papers: The GRAVITY metrology system: narrow-angle astrome…

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Light pulse atom interferometers (AIFs) are exquisite quantum probes of spatial inhomogeneity and gravitational curvature. Moreover, detailed measurement and calibration are necessary prerequisites for very-long-baseline atom interferometry…

Quantum Physics · Physics 2026-03-30 Michael Werner , Ali Lezeik , Dennis Schlippert , Ernst Rasel , Naceur Gaaloul , Klemens Hammerer

This letter presents a dual quadrature phasemeter, an implementation of a phase-locked loop designed to track the phase of homodyne and heterodyne inter-satellite laser links. The dual quadrature phasemeters use dual quadrature optical…

Optics · Physics 2024-10-30 Callum S. Sambridge , Kirk McKenzie

Aims. As part of the ongoing GRAVITY+ upgrade of the Very Large Telescope Interferometer infrastructure, we aim to improve the performance of the GRAVITY Fringe-Tracker, and to enable its use by other instruments. Methods. We modify the…

Scaling up interferometry to 8m collectors should smooth-out the optical piston perturbations and allow a slow fringe tracker to obtain high precision correction on faint targets. In practice, the GRAVITY fringe tracker still observes high…

Neutron grating interferometry provides information on phase and small-angle scatter in addition to attenuation. Previously, phase grating moir\'e interferometers (PGMI) with two- or three-phase gratings have been developed. These…

Instrumentation and Detectors · Physics 2023-04-19 I. J. Hidrovo , J. Dey , H. Meyer , D. S. Hussey , N. N. Klimov , L. G. Butler , K. Ham , W. Newhauser

Doppler orbitography uses the Doppler shift in a transmitted signal to determine the orbital parameters of satellites including range and range-rate (or radial velocity). We describe two techniques for atmospheric-limited optical Doppler…

Instrumentation and Methods for Astrophysics · Physics 2020-06-09 Benjamin P. Dix-Matthews , Sascha W. Schediwy , David R. Gozzard , Simon Driver , Karl Ulrich Schreibe , Randall Carman , Michael Tobar

The dispersed fixed-delay Intereferometer (DFDI) method is attractive for its low cost, compact size, and multiobject capability in precision radial-velocity (RV) measurements. The phase shift of fringes of stellar absorption lines is…

Instrumentation and Methods for Astrophysics · Physics 2015-05-28 Ji Wang , Jian Ge , Xiaoke Wan , Brian Lee , Nathan De Lee

A novel method capable of delivering relative optical path length metrology with nanometer precision is demonstrated. Unlike conventional dual-wavelength metrology which employs heterodyne detection, the method developed in this work…

Instrumentation and Methods for Astrophysics · Physics 2015-06-15 Yitping Kok , Michael J. Ireland , J. Gordon Robertson , Peter G. Tuthill , Benjamin A. Warrington , William J. Tango

We propose a numerical interferometry method for identification of optical multiply-scattering systems when only intensity can be measured. Our method simplifies the calibration of optical transmission matrices from a quadratic to a linear…

Signal Processing · Electrical Eng. & Systems 2020-02-17 Sidharth Gupta , Rémi Gribonval , Laurent Daudet , Ivan Dokmanić

Astrometry is a powerful technique in astrophysics to measure three-dimensional positions of stars and other astrophysical objects, including exoplanets and the gravitational influence they have on each other. Interferometric astrometry is…

Instrumentation and Methods for Astrophysics · Physics 2018-12-10 Michael J. Ireland , Julien Woillez

Atom interferometers are powerful tools for both measurements in fundamental physics and inertial sensing applications. Their performance, however, has been limited by the available interrogation time of freely falling atoms in a…

Dual-field interferometric observations with VLTI/GRAVITY sometimes require the use of a "binary calibrator", a binary star whose individual components remain unresolved by the interferometer, with a separation between 400 and 2000 mas for…

Sample-induced aberrations and optical imperfections limit the resolution of fluorescence microscopy. Phase diversity is a powerful technique that leverages complementary phase information in sequentially acquired images with deliberately…

We present a new scheme for measuring the differential phase in dual atom interferometers. The magnetic field is modulated in one interferometer, and the differential phase can be extracted without measuring the amplitude of the magnetic…

Atomic Physics · Physics 2016-06-22 Yu-Ping Wang , Jia-Qi Zhong , Xi Chen , Run-Bing Li , Da-Wei Li , Lei Zhu , Hong-Wei Song , Jin Wang , Ming-Sheng Zhan

The limiting magnitude is a key issue for optical interferometry. Pairwise fringe trackers based on the integrated optics concepts used for example in GRAVITY seem limited to about K=10.5 with the 8m Unit Telescopes of the VLTI, and there…

Medical differential phase contrast x-ray imaging (DPCI) promises improved soft-tissue contrast at lower x-ray dose. The dose strongly depends on both the angular sensitivity and on the visibility of a grating-based Talbot-Lau…

Medical Physics · Physics 2016-03-23 Oliver Preusche

This publication presents a novel interferometric method for the simultaneous spatially resolved analysis of an object under test regarding the phase transmission function and the magnitude and orientation of dichroism. Analogous to the…

Optics · Physics 2018-12-12 Sergej Rothau , Xiao Rao , Norbert Lindlein

We have realized an atom interferometer that probes gravitational potentials by holding, rather than dropping, atoms. Up to one minute of coherence times are realized by suspending the spatially separated atomic wave packets in an optical…

Atomic Physics · Physics 2023-02-01 C. D. Panda , M. Tao , J. Eggelhof , M. Ceja , A. Reynoso , V. Xu , H. Muller

In the presence of Earth gravity and gravity-gradient forces, centrifugal and Coriolis forces caused by the Earth rotation, the phase of the time-domain atom interferometers is calculated with accuracy up to the terms proportional to the…

Atomic Physics · Physics 2009-11-11 B. Dubetsky , M. A. Kasevich

This paper discusses a novel approach for detecting moving massive objects based on the time variation that these objects produce in the local gravitational field measured by several detectors. Such an approach may provide a viable method…

Instrumentation and Detectors · Physics 2012-08-14 Emmanuel David Tannenbaum